The latest round of browser releases put a heavy focus on JavaScript performance, so what does the next round have in store? Only time will tell, but come late 2010, Firefox 4.0 will hit the streets if everything goes to plan.

According to Mozilla's recently released roadmap, Firefox 4.0 will first show up in beta form around June of next year, with a final release planned for October or November. The usual round of speed and responsiveness tweaks will be part of the next-gen browser, in addition to a new extensibility platform Mozilla is calling 'JetPack.' But the biggest change might be the Chrome-like handling of tabs, where each tab functions as its own separate process.

Between now and then, Mozilla plans to release Firefox 3.6 before the end of 2009 (you can already snag the Alpha 1 build here), which will feature Windows 7 integration, lightweight themes, asynchronous location bar, improved scrolling model on Windows, startup optimizations, and more. Then in early 2010, Firefox 3.7 will bring out-of-process plugins to the table, as well as book synchronization, task oriented browsing, the ability to run websites as an application, and other improvements.